FDIC Indemnification Asset (Details) (USD $)	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Receivable from FDIC for Loss Share Agreements
Balance at the beginning of the period	$ 146,171,000	$ 262,651,000
Increase (decrease) in expected losses on loans	(1,062,000)	2,310,000
Additional losses on OREO	841,000	6,779,000
Reimbursable expenses	1,097,000	2,674,000
Amortization of discounts and premiums, net	(7,171,000)	(3,233,000)
Cash received from loss share claims filed, including reimbursable expenses	(15,536,000)	(39,850,000)
Balance at the end of the period	124,340,000	231,331,000
Projected shortfall in cash flows related to FDIC indemnification asset for losses on assets acquired	47,300,000
Subsequent Event
Receivable from FDIC for Loss Share Agreements
Cash received from loss share claims filed, including reimbursable expenses	13,000,000
Habersham
Receivable from FDIC for Loss Share Agreements
Estimated "true-up" payment to the FDIC at the end of the loss share agreement	0
BankMeridian
Receivable from FDIC for Loss Share Agreements
Estimated "true-up" payment to the FDIC at the end of the loss share agreement	3,700,000
FDIC Indemnification Asset True-up Period	10 years
CBT
Receivable from FDIC for Loss Share Agreements
Estimated "true-up" payment to the FDIC at the end of the loss share agreement	$ 0